In the past, metal molding relied on filling a cavity with molten metal and then allowing the metal to cool. A feeder tube is used to direct the molten metal into the cavity. Unfortunately, oxides form as a result of exposure of the molten metal to the material comprising the feeder tube. These oxides then find their way into the mold cavity along with the desired alloy. This causes an undesired effect in the resultant molded part in that the oxides weaken the final molded component.
Another problem that has not yet been addressed is that the flow of molten metal into the feeder tube is not controlled. Turbulent flow of the metal causes voids in the final molded part, again weakening its structural characteristics.